This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention that are described and claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
There are several places worldwide, such as Western Europe, the United States of America and Canada, for example, where public power networks are generally reliable. Specifically, the public power networks provide a line voltage that experiences little variance, and any variances that do occur typically result from environmental factors. However, in emerging markets, such as China and India, for example, there are known power network quality issues. In particular, line voltage variance in the form of high line voltages as much as two times the nominal line voltage may commonly occur. These high line voltage events may have durations of a few milliseconds up to several hours.
As electronic products are increasingly being shipped to the emerging markets, manufacturers are encountering increased warranty repair costs due to the power network quality issues. Specifically, the high line voltage events, even those lasting for only milliseconds, have been proven to pose reliability issues. Conventionally, techniques to improve immunity to high line voltage events include using higher voltage rated components and/or adding a passive power factor controller (PFC) choke. These components are not standard or common and, as such, are more expensive, resulting in increased manufacturing costs for the power supplies implementing these techniques. Additionally, adding a passive PFC choke significantly increases the weight of the device, resulting in increased freight costs. Furthermore, customization of the power supply segment makes it difficult to leverage volume cost advantages, and increases the supply chain complexity, cost, inventory, etc.